Hysteresis in heating or cooling system control is the temperature difference between the system's switch-on and switch-off points. This value is crucial to ensure the system's efficient operation and long life.
How does hysteresis work?
Hysteresis prevents the system from turning on and off too frequently, which could be caused by constant temperature fluctuations.
Example of a heating system:
- Target temperature: 22 °C
- Hysteresis: ±2 °C
- Power on: When the room temperature drops below 20°C, the system turns on.
- Shutdown: When the room temperature reaches 24°C, the system shuts down.
This mechanism ensures that the system does not operate continuously in the event of minor temperature changes, which saves energy and reduces wear and tear on the equipment.
Why is hysteresis important?
Energy efficiency: Properly setting the hysteresis reduces system energy consumption by minimizing the number of on and off cycles.
Equipment life: Too frequent operation increases wear on system components, while hysteresis helps maintain their condition.
Stable operation: Hysteresis prevents too frequent temperature fluctuations, ensuring a stable and comfortable indoor climate.
How to set hysteresis?
Hysteresis too narrow: If the difference is too small (e.g. ±0.5 °C), the system will turn on and off too often, increasing wear and tear and energy consumption.
Hysteresis too wide: If the difference is too large (e.g. ±5 °C), the room temperature may vary uncomfortably.
Optimal setting: A hysteresis value of ±1–2 °C is generally recommended for domestic systems, but the exact value depends on the specific system and user needs.
Example of hysteresis values
| System type | Optimal hysteresis (°C) |
|---|---|
| Heating system (boiler) | ±1–2 |
| Heat pump | ±2–3 |
| Air conditioner | ±1–2 |
| Industrial temperature control | ±0.5–1 |
Summary
Hysteresis is the key to efficient operation of heating and cooling systems. When set correctly, it minimizes energy consumption, extends the life of the equipment, and ensures a stable indoor climate. Optimizing the hysteresis value depends on the type of system and energy demand, so it is important to consider this parameter when installing and operating the system.